A number of conditions are known which impair certain centres of the brain dealing with memory or visualisation, co-ordination, and other non-verbal functions. As examples of this are Alzheimer's, Parkinson's disease, epilepsy as well as physical trauma. Typically such impairments are predominantly in the right temporal lobe. As non-verbal impairments are often difficult to characterise, tests have been devised to assist in the assessment. Some of the tests combine assessments of motor impairment and also memory.
In the past 80 years a number of tasks have been developed many of them based around the graphic reproduction of a relatively complex 2-D line drawing: both with the original visible to the test subject and also following a timed delay after having seen the drawing. One of the central images used in this respect is the Rey-Osterrieth Complex Figure Test (ROOF). The image comprises a large number of geometrical shapes, assembled together, but without reference to any physical object with which the subject might be acquainted. There are many ways of using the ROOF test. For example, clinical experts can assess the accuracy with which lines are drawn, the relational positions and orientation of elements within the image, the speed of drawing, etc. Records of the order in which tines are drawn can be made and assessed. In addition, a subject can be provided with drawing implements of different colour and the use of these assessed.
As a variant of this, the investigator may switch the drawing implement after a preset time to determine the subject's response and how the interruption affects the ability to carry out the task.
Amongst other figure tests used, can be named the Georgian College Complex Figure Test, the Taylor Complex Figure Test etc. A relatively simple figure test, and one particularly suited to the present invention is the Benson Figure Test, as reproduced in FIG. 1.
To date the Benson Figure Test is completed on paper, possible as part of a wider series of tests. An assessment is made of the abilities of the subject in accordance with a preset list of categories and grading. Nevertheless the assessment normally needs to be made by a qualified clinician and the assessment method is relatively subjective.
It is an object of the present invention to provide a device which is usable, even by less qualified personnel to give an accurate assessment of a person's abilities and also, in certain embodiments to provide a diagnosis of the subject's condition.